Many different types of mechanical, electromechanical, and electronic display devices are known and have been developed over the years in the field of the present technology.
In Levy, et al U.S. Pat. No. 3,267,595, a display unit is disclosed that can be provided with a plurality of different types of display elements and triggering mechanisms for moving the display elements to change the display. In one embodiment, Levy, et al includes a moving belt of rows and columns of rotatable rectangular-lie display elements, whereby for each row of display elements, a solenoid-operated trigger finger is selectively activated for flipping over (rotating by 180.degree.) selective ones of the elements for changing the information being displayed. A mechanical cam mechanism 24 (see FIG. 6) is used to hold a given display element 23 in appropriate alignment in the display for displaying information through appropriate positioning of the various ones of the elements 23 in the matrix. In FIG. 8, a control system is shown for controlling selective activation of the various electromagnetic triggers for selectively flipping the display elements 23. In another embodiment, triangular display elements are shown in FIG. 9 for providing three-faced elements, nd are used in combination with a pair of solenoid operated trigger pins to rotate selected ones of the triangles from one display position to another. Four-faced display elements 60, as shown in FIG. 11, represent another embodiment which requires three solenoid-operated "triggers" for selectively rotating a given four-faced element or block, and three "reset fingers" are required for resetting the elements. Each element of Levy's four-faced elements appear to be cube-like, and to have four unique faces. Also, Levy rotates the belt of display elements past stationery solenoid-operated triggers for changing the elements rotational orientation, to change a given display. Another embodiment of Levy, et al (see FIG. 26) shows a fixed matrix of display elements 160, with a carriage mechanism provided at the back of the display 160, for moving a plurality of solenoid-operated fingers back and forth across the back of the display element, for selectively flipping various ones of the display elements 180' for providing a desired display on the front of the display unit. As shown in FIG. 27, the elements 161 each include two lugs for providing automatic resetting, whereby when a given one of the lugs 175 or 176 contact an arm 171 of a solenoid 172, the element is flipped 180.degree. to change the face of the element being presented on the display side of the display unit.
In Anderson et al, U.S. Pat. No. 4,091,382, a display system is disclosed that is made up of a plurality of display units each including a thin, pivotally-mounted vane 20 movable by electrostatic forces between upright and horizontal positions, for selectively providing a desired display. Also, in Winrow U.S. Pat. No. 3,975,728, an electromagnetic display is taught that includes a plurality of display elements each including a disc that is pivotally mounted on an axis parallel to the mean plane of the display, whereby electromagnetic means are used to rotate the disc for providing a desired display.
In Bergamini U.S. Pat. No. 4,161,832, an electromechanical digital indicator for displaying numerical information is disclosed, in which angular movements of seven movable segments are combined with the action of a block in the shape of an eight and made of a transparent and light-channeling plastic material, to display selected figures from zero to nine in solid lines rather than in segmented form. Fluorescent layers on the bottom wall of the block are included for displaying the numerals under conditions of either direct or indirect lighting, or in darkness. Also, internal illumination can be provided on the interior portion of the indicator box.
In Wakatake U.S. Pat. No. 4,177,458 a display panel, is shown to include a plurality of display elements that are rotatable in a vertical plane. The elements are formed from plate-like or four-cornered block members having two or four display surfaces of different colors and include one or three magnetic pieces, respectively. Up to three electromagnets are energized for permitting the selection of a particular face of a given display element by rotation to the display side of the display panel. In this manner, a desired pattern can be displayed. In a later Wakatake U.S. Pat. No. 4,264,906, similar display elements are shown that have display surfaces of different colors, providing displays of desired characters or patterns in the display side of the display panel.
In Siebert, et al U.S. Pat. No. 4,389,804, a matrix of individually activated flip discs are provided for a display. Magnetic forces are utilized with each disc for moving the associated disc between a reflective position exposing one disc surface at the front of the panel, to a closed condition exposing an opposite surface at the front of the panel, and lastly to an intermediate position permitting backlighting.
In Wakatake U.S. Pat. No. 4,417,241, a display panel is disclosed consisting of a matrix of rotatable block-like members each having up to four different display surfaces. Each block member has a plurality of magnetic pieces attached to it for selective coaction with electromagnets mounted on a movable carriage mechanism, for providing selective positioning of each display element to form a desired pattern on the front of the display panel.
In Wakatake U.S. Pat. No. 4,566,003, a plurality of display elements are formed into a drum-like display panel, wherein each of the elements consists of a four-sided right prismatic block member which is rotatable about its own central axis. Two stable states are provided for each one of the display elements. Permanent magnets are attached to each one of the block members for coaction with a stationary electromagnetic actuator system about which the display elements or blocks revolve. The electromagnetic triggering mechanism is selectively activated for rotating the display elements to a desired position.
In Wakatake U.S. Pat. No. 4,615,131, a matrix of rotatable block-like display elements is disclosed for providing a display panel. Each of the display elements has a permanent magnet type motor associated with that element, which motor is activated for positioning a particular face of the block at the front of the display for permitting a desired pattern to be displayed by selective positioning of each block.
Wood U.S. Pat. No. 4,616,222 teaches a system for providing a display that consists of a plurality of rotatable display elements each consisting of relatively thin rectangular-like elements. Each element is generally planar. Electromagnetic solenoids associated with each of the display elements, respectively, are selectively activated to rotate associated elements 180.degree., for obtaining a desired pattern on the surface of the display.